Due to the technical advantages of no backlight source, high contrast, small thickness, large visual angle and fast reaction speed, etc., Organic Light-Emitting Display has become one of the important development directions of the display industries.
The existing organic light-emitting display panel includes: a cathode, an electron transport layer, a light-emitting layer, a hole transport layer, an anode and a substrate. During operation, a bias voltage is applied between the anode and the cathode of the organic light-emitting display panel, so that holes and electrons can break through the interfacial energy barrier and migrate respectively from the hole transport layer and the electron transport layer to the light-emitting layer, and on the light-emitting layer, electrons and holes are recombined to generate excitons. The excitons are unstable, and energy can be released. The energy is transferred to the molecules of the organic light-emitting material in the light-emitting layer, so that the molecules transit from a ground state to an excited state. The excited state is very unstable, and thus the excited molecules return to the ground state from the excited state, so that a light emitting phenomenon appears due to radiative transition. In the organic light-emitting display panel, the number of injected carriers as well as the lightness and efficiency of the organic light-emitting display panel are determined by the interfacial energy barrier between the organic material and the electrodes. However, in the existing organic light-emitting display panel, due to the too high interfacial energy barrier between the hole injection layer and the anode, the injection capacity of holes is small, which will cause the poor performance of the organic light-emitting display panel.